Blade structure for torque converter and manufacturing method of blade structure for torque converter

ABSTRACT

A first connecting portion  16  that contacts an inner peripheral wall of an annular turbine shell  10  and connects blades  12,  and a second connecting portion  14  that contacts the turbine shell  10  further toward an outside in a diametrical direction of the turbine shell  10  than the first connecting portion  16  and connects the blades  12  are provided, and a blade structure  11  in which the blades  12  are integrated by the first connecting portion  16  and the second connecting portion  14  is attached to the turbine shell  10.

FIELD OF THE INVENTION

This invention relates to a blade structure for a torque converter and a method of manufacturing a blade structure for a torque converter.

BACKGROUND OF THE INVENTION

JP2001-141028A discloses a conventional device in which one end portion side of a blade of a torque converter and a link-shaped connecting portion are connected by a branch portion, and the resulting blade structure is attached to a shell member of the torque converter.

SUMMARY OF THE INVENTION

However, in the invention described above, a single blade structure is formed by punching out a plurality of blades from a band-shaped plate and joining one end portion of the band-shaped plate to which the blades are connected by welding or the like. Therefore, one end portion of the blades is in a released state such that when the blade structure is attached to the shell member, the blade structure must be attached while positioning the blades in blade attachment positions of the shell member. As a result, operational efficient deteriorates.

This invention has been designed to solve this problem, and it is an object thereof to enable the blades of a blade structure comprising a plurality of integrated blades to be attached easily to a shell member.

This present invention provides a blade structure for a torque converter which comprises a plurality of blades attached fixedly to an inner wall of an annular shell member at predetermined intervals in a circumferential direction of the shell member. The blade structure comprises a first connecting portion that contacts the inner wall of the shell member and connects the blades, and a second connecting portion that contacts the inner wall of the shell member further toward an outside in a diametrical direction of the shell member than the first connecting portion and connects the blades. The plurality of blades are connected integrally by the first connecting portion and the second connecting portion, and by joining the first connecting portion and the second connecting portion to the shell member, the plurality of blades are attached fixedly to the shell member.

This present invention provides also a manufacturing method of a blade structure for a torque converter which comprises a plurality of blades attached fixedly to an inner wall of an annular shell member at predetermined intervals in a circumferential direction of the shell member. The method comprises a step of punching for punching out, from a planar thin plate, respective shapes of the plurality of blades, a first connecting portion that contacts an inner peripheral side of the shell member and connects the blades, and a second connecting portion that contacts the shell member further toward an outside in a diametrical direction of the shell member than the first connecting portion and connects the blades, a step of a first bending for bending the blades between the first connecting portion and the second connecting portion, a step of a second bending for tilting the blades at a predetermined angle relative to the first connecting portion and the second connecting portion, and a step of a first narrowing for processing the first connecting portion to modify a distance between adjacent blades near the first connecting portion.

According to this invention, the blades are connected to the first connecting portion and second connecting portion, and therefore, when the blade structure is attached to the shell member, the blades can be positioned relative to the shell member easily, enabling an improvement in operational efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic constitutional view showing a torque converter according to a first embodiment of this invention.

FIG. 2A is a front view of a blade structure according to the first embodiment of this invention seen from a pump impeller.

FIG. 2B is a sectional view of the blade structure.

FIG. 3 is a flowchart showing a molding process for forming the blade structure according to the first embodiment of this invention.

FIG. 4A is a front view of the blade structure according to the first embodiment of this invention.

FIG. 4B is a sectional view of the blade structure according to the first embodiment of this invention.

FIG. 5A is a front view of the blade structure according to the first embodiment of this invention.

FIG. 5B is a sectional view of the blade structure according to the first embodiment of this invention.

FIG. 6A is a front view of the blade structure according to the first embodiment of this invention.

FIG. 6B is a sectional view of the blade structure according to the first embodiment of this invention.

FIG. 7 is a front view of a blade structure according to a second embodiment of this invention seen from a pump impeller.

FIG. 8 is a flowchart showing a forming process for forming the blade structure according to the second embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The constitution of a torque converter according to a first embodiment of this invention will be described using FIG. 1. A torque converter 1 is a fluid coupling disposed between an engine and an automatic transmission of a vehicle.

The torque converter 1 of this embodiment comprises a front cover 2 to which rotation from the engine, not shown in the drawing, is transmitted, a rear cover 3 that is attached to the front cover 2 and rotates integrally with the front cover 2, a pump impeller 4 provided on an inner wall of the rear cover 3, a turbine runner 5 disposed so as to face the pump impeller 4, and an output shaft 6 that transmits the rotation of the turbine runner 5 to the automatic transmission (not shown).

The turbine runner 5 comprises a substantially annular turbine shell (shell member) 10 and a blade structure 11 that is joined to the turbine shell 10.

The blade structure 11 will now be described using FIG. 2A and FIG. 2B. FIG. 2A is a front view of the blade structure 11 seen from the pump impeller 4, and FIG. 2B is a sectional view of the blade structure 11.

The blade structure 11 comprises a plurality of blades 12 disposed in a circumferential direction of the substantially annular turbine shell 10, an annular first connecting portion 16 that is joined to an inner wall of the turbine shell 10 and connected to the blades 12 via first branch portions 15, and an annular second connecting portion 14 that is joined to the inner wall of the turbine shell 10 further toward an outside in a diametrical direction of the turbine shell 10 than the first connecting portion 16, and connected to the blades 12 via second branch portions 13.

The blades 12, the first connecting portion 16 and the second connecting portion 14 are formed from a single plate, as will be described in detail below.

The first connecting portion 16 comprises first adjustment portions 18 disposed in the circumferential direction of the turbine shell 10 for adjusting the distance between adjacent blades 12.

The first adjustment portions 18 are formed by deforming a part of the first connecting portion 16 in a diametrical direction of the first connecting portion 16 by means of pressing using a die or the like. By providing the first adjustment portions 18, the distance between adjacent blades 12 is reduced, and thus the distance between the blades 12 can be adjusted. It should be noted that the first adjustment portions may be formed by deforming a part of the first connecting portion 16 so that it projects in an axial direction, and the projecting part may be cut by pressing, laser and so on.

Each blade 12 comprises a projecting portion 17 that fits into a groove provided in the turbine shell 10. In the torque converter 1, the blade 12 is bent into a shape for generating a desired flow in a fluid and is attached to the turbine shell 10 at a predetermined angle. When the projecting portion 17 is fitted into the groove, the position of the blade 12 in the diametrical direction and circumferential direction of the turbine shell 10 is positioned such that adjacent blades 12 are disposed at predetermined intervals. In other words, the projecting portion 17 determines the position of the blade 12 relative to the turbine shell 10.

In the blade structure 11, the first connecting portion 16 and second connecting portion 14 are welded to the turbine shell 10, whereas the blades 12 positioned by the projecting portions 17 are soldered to the turbine shell 10. The joints between the turbine shell 10 and the first connecting portion 16, the joints between the turbine shell 10 and second connecting portion 14, and the joints between the blades 12 and the turbine shell 10 do not have to be formed by these methods, and the blade structure 11 may be joined to the turbine shell 10 by any method as long as the performance of the torque converter 1 is maintained.

As described above, the blade structure 11 is formed by integrating the first connecting portion 16 and second connecting portion 14 with the blades 12 via the first branch portions 15 and the second branch portions 13, and therefore, when the blade structure 11 is attached to the turbine shell 10, the blades 12 can be positioned in the grooves of the turbine shell 10 easily.

Next, a forming process for forming the blade structure 11 will be described using FIGS. 2A to 8A and FIGS. 2B to 8B. FIG. 3 is a flowchart showing a molding process for the blade structure 11. FIGS. 4A to 6A are front views of the blade structure 11 during each process, and FIGS. 4B to 6B are sectional views of the blade structure 11 during each process.

In a step S100, a punching process is performed. In this process, a single metal plate is punched by pressing to form the first connecting portion 16, the second connecting portion 14, the plates 12 and so on (FIG. 4A and FIG. 4B).

In a step S101, a first bending process is performed. In this process, the plates 12 are pressed using a die to bend the blades 12 into a predetermined shape (FIG. 5A and FIG. 5B). By means of this process, the shape of the blades 12 upon attachment of the blade structure 11 to the turbine shell 10 is substantially formed.

In a step S102, a second bending process is performed. In this process, the blade structure 11 formed in the step S101 is pressed using a die such that the blades 12 are rotated relative to the first connecting portion 16 and second connecting portion 14 (FIG. 6A and FIG. 6B). By means of this process, the angle of the blades 12 relative to the turbine shell 10 when the blade structure 11 is attached to the turbine shell 10 is determined.

In a step S103, a first narrowing process is performed. In this process, pressing is performed using a die to deform a part of the first connecting portion 16 in the diametrical direction, thereby forming the first adjustment portions 18. Following deformation, the part may be cut away. By means of this process, a part of the diameter of the first connecting portion 16 is reduced, and accordingly, the distance between adjacent blades 12 decreases. Thus, the distance between the blades 12 can be adjusted (FIG. 2A and FIG. 2B). It should be noted that the deformation direction is not limited to that shown in FIG. 2A, and deformation may be performed in any direction that reduces the distance between adjacent blades 12.

In a step S104, a third bending process is performed. In this process, the first connecting portion 16 and second connecting portion 14 are pressed in alignment with an inner wall of the turbine shell 10. By means of this process, the second connecting portion 14 is tilted relative to the first connecting portion 16 in alignment with the inner wall of the turbine shell 10.

The blade structure 11 formed in this manner is positioned relative to the turbine shell 10 by caulking the projecting portions 17 of the blades 12 to the grooves in the turbine shell 10, and then attached fixedly to the turbine shell 10 through soldering or welding.

By means of the processes described above, a blade structure 11 that can be attached easily to the turbine shell 10 can be formed from a single planar flat plate.

The effects of the first embodiment of this invention will now be described.

In this embodiment, the blades 12 are connected to the first connecting portion 16 via the first branch portions 15 and connected to the second connecting portion 14 via the second branch portions 13, thereby producing a blade structure 11 in which the blades 12 are connected integrally. Hence, when the blade structure 11 is attached to the turbine shell 10, the positions of the grooves provided in the turbine shell 10 and the positions of the blades 12 can be aligned easily, enabling an improvement in the efficiency of an operation to attach the blade structure 11 to the turbine shell 10.

The blades 12 are provided with the projecting portions 17 that project from the contact surface between the blades 12 and the turbine shell 10 and fit into the grooves provided in the turbine shell 10. Hence, when the blade structure 11 is attached to the turbine shell 10, the blades 12 can be positioned relative to the turbine shell 10 by fitting the projecting portions 17 into the grooves. As a result, the blade structure 11 can be attached to the turbine shell 10 easily, enabling an improvement in operational efficiency.

By providing the first connecting portion 16 with the first adjustment portions 18, the distance between adjacent blades 12, i.e. the distance between adjacent blades 12 in the vicinity of the first connecting portion 16 and second connecting portion 14, can be adjusted.

By tilting the first connecting portion 16 and second connecting portion 14 in alignment with the inner wall of the turbine shell 10, the blade structure 11 can be attached to the turbine shell 10 easily, enabling an improvement in operational efficiency.

A second embodiment of this invention will now be described using FIG. 7. FIG. 7 is a front view of the blade structure 11 according to this embodiment, seen from the pump impeller 4.

The blade structure 11 of this embodiment comprises second adjustment portions 20 for adjusting the distance between adjacent blades 12. All other constitutions are similar to the constitutions of the first embodiment, and description thereof has been omitted.

The second adjustment portions 20 are formed by deforming a part of the second connecting portion 14 in the diametrical direction of the second connecting portion 14 by means of pressing using a die or the like. By providing the second adjustment portions 20, the distance between adjacent blades 12 is reduced, and thus the distance between the blades 12 can be adjusted. It should be noted that the second adjustment portions 20 may be formed by deforming a part of the second connecting portion 14 in the axial direction, and the projecting second adjustment portions 20 may be cut using pressing, laser and so on.

Next, a forming process for forming the blade structure 11 of this embodiment will be described using FIG. 8.

A step S200 to a step S203 are identical to the steps S100 to S103 of the first embodiment, and therefore description thereof has been omitted.

In a step S204, a second narrowing process is performed. In this process, the second connecting portion 14 is pressed using a die to deform a part of the second connecting portion 14 in the diametrical direction, thereby forming the second adjustment portions 20. As a result, a part of the diameter of the second connecting portion 14 is reduced, and accordingly, the distance between adjacent blades 12 decreases. Thus, the distance between the blades 12 can be adjusted. In particular, the distance between adjacent blades 12 in the vicinity of the second connecting portion 14 can be adjusted. It should be noted that the deformation direction is not limited to that shown in FIG. 7, and deformation may be performed in any direction that reduces the distance between adjacent blades 12.

In a step S205, a third bending process is performed. In this process, the first connecting portion 16 and second connecting portion 14 are pressed in alignment with the inner wall of the turbine shell 10. By means of this process, the second connecting portion 14 is tilted relative to the first connecting portion 16 in alignment with the inner wall of the turbine shell 10.

It should be noted that the distance between the blades 12 may be adjusted by providing the second adjustment portions 20 alone.

The effects of the second embodiment of this invention will now be described.

In this embodiment, the second adjustment portions 20 are formed on the second connecting portion 14, and thus the distance between adjacent blades 12 can be reduced. Hence, the distance between adjacent blades 12 in both the vicinity of the first connecting portion 16 and the vicinity of the second connecting portion 16 can be modified.

This application claims priority from Japanese Patent Application 2007-092365, filed Mar. 30, 2007, which is incorporated herein by reference in its entirety. 

1. A blade structure for a torque converter, in which a plurality of blades are attached fixedly to an inner wall of an annular shell member at predetermined intervals in a circumferential direction of the shell member, comprising: a first connecting portion that contacts the inner wall of the shell member and connects the blades; and a second connecting portion that contacts the inner wall of the shell member further toward an outside in a diametrical direction of the shell member than the first connecting portion and connects the blades, wherein the plurality of blades are connected integrally by the first connecting portion and the second connecting portion, and by joining the first connecting portion and the second connecting portion to the shell member, the plurality of blades are attached fixedly to the shell member.
 2. The blade structure for a torque converter as defined in claim 1, wherein the blades each comprise a projecting portion that projects from a surface that contacts the shell member and fits into a groove provided in the shell member, thereby positioning the blade relative to the shell member.
 3. The blade structure for a torque converter as defined in claim 2, wherein the projecting portion is caulked to the groove provided in the shell member, and the first connecting portion or the second connecting portion is welded to the shell member.
 4. The blade structure for a torque converter as defined in claim 1, wherein the first connecting portion has an annular shape and the second connecting portion has an annular shape larger than that of the first connecting portion.
 5. The blade structure for a torque converter as defined in claim 4, wherein the first connecting portion comprises a first adjustment portion that adjusts a distance between adjacent blades.
 6. The blade structure for a torque converter as defined in claim 5, wherein the first adjustment portion projects in an axial direction of the first connecting portion so as to modify a diameter of the first connecting portion.
 7. The blade structure for a torque converter as defined in claim 5, wherein the first adjustment portion projects in a diametrical direction of the first connecting portion so as to modify the diameter of the first connecting portion.
 8. The blade structure for a torque converter as defined in claim 5, wherein the first adjustment portion is formed by die forming.
 9. The blade structure for a torque converter as defined in claim 4, wherein the second connecting portion comprises a second adjustment portion that adjusts a distance between adjacent blades.
 10. The blade structure for a torque converter as defined in claim 9, wherein the second adjustment portion projects in an axial direction of the second connecting portion so as to modify a diameter of the second connecting portion.
 11. The blade structure for a torque converter as defined in claim 9, wherein the second adjustment portion projects in a diametrical direction of the second connecting portion so as to modify the diameter of the second connecting portion.
 12. The blade structure for a torque converter as defined in claim 9, wherein the second adjustment portion is formed by die forming.
 13. The blade structure for a torque converter as defined in claim 1, wherein the second connecting portion is inclined relative to the first connecting portion.
 14. A manufacturing method of a blade structure for a torque converter which has a plurality of blades attached fixedly to an inner wall of an annular shell member at predetermined intervals in a circumferential direction of the shell member, the method comprising: a step of punching for punching out, from a planar thin plate, respective shapes of the plurality of blades, a first connecting portion that contacts the inner wall of the shell member and connects the blades, and a second connecting portion that contacts the inner wall of the shell member further toward an outside in a diametrical direction of the shell member than the first connecting portion and connects the blades; a step of a first bending for bending the blades between the first connecting portion and the second connecting portion; a step of a second bending for tilting the blades at a predetermined angle relative to the first connecting portion and the second connecting portion; and a step of a first narrowing for processing the first connecting portion to modify a distance between adjacent blades near the first connecting portion.
 15. The manufacturing method of a blade structure for a torque converter as defined in claim 14, further comprising a step of a second narrowing for processing the second connecting portion to modify a distance between adjacent blades near the second connecting portion. 